Generally, an internal combustion engine is provided with a lubrication system for lubricating and cooling, and the lubrication system circulates oil through various parts of the engine. While oil circulates in the engine, it gathers impurities. To remove such impurities, an oil filter assembly is provided within the lubrication system.
A convention oil filter assembly includes a filter housing and an oil filter that is disposed within the filter housing. If too many impurities are accumulated in the oil filter, the oil filter cannot operate normally. Therefore, the oil filter must be exchanged.
Generally, the filter housing is configured to drain oil existing therein to an oil pan when the oil filter is being exchanged. An oil exhaust passageway communicating with a main oil gallery is formed in a lower portion of the filter housing, and an oil drain hole is branched from the oil exhaust passageway. The oil drain hole communicates with the oil pan.
In a state that the oil filter is mounted, a lower portion of a filter stand that supports the oil filter is inserted into the oil drain hole, and a sealing ring is coupled to an outer circumference of the filter stand, so that the oil drain hole is closed.
The oil filter stand is also exchanged when the oil filter is exchanged. Therefore, when the oil filter is removed from the filter housing, the oil drain hole is opened, so that oil in the oil filter housing moves into the oil pan through the oil drain hole.
At this time, oil also flows into the main oil gallery through the oil exhaust passageway. Therefore, unfiltered oil flows into the engine. That is, while the oil filter is exchanged, unfiltered oil may flow into the main oil gallery, and this can cause engine troubles.
Furthermore, the filter stand must be extended to the oil drain hole in order to close the oil drain hole when the oil filter is mounted. Therefore, the filter stand is long so that there are difficulties in mounting the oil filter.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.